From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-20.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8486EC433ED for ; Tue, 18 May 2021 17:31:56 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E905260C41 for ; Tue, 18 May 2021 17:31:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E905260C41 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:49546 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lj3ZT-0006Dq-0r for qemu-devel@archiver.kernel.org; Tue, 18 May 2021 13:31:55 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:35550) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lj3YO-0005NA-ML for qemu-devel@nongnu.org; Tue, 18 May 2021 13:30:48 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:58132) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lj3YC-0002M8-TC for qemu-devel@nongnu.org; Tue, 18 May 2021 13:30:47 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1621359036; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=kL+I+n3YrQa/nBlKIhoO90ZBjyy5YXDUASctktCP/O0=; b=RPm+4PrHM+t7NTMY9SMw73geEFXY2MwREwfecqIZgqNYjhkfMXFT8Gh7+05U0IEGTmQl8H Bw+P8WKK9PowOQ+X2x1FOGGpte2ISxTOzmius+doeCWt3xxoTP2X7HTJA73Wertf7xfM0j gfFfBbGpLSYMh8YBF6p9aZfbv9y9hV0= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-471-RoJoPvldPw-wqGvJFag7TQ-1; Tue, 18 May 2021 13:30:32 -0400 X-MC-Unique: RoJoPvldPw-wqGvJFag7TQ-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id CD89F107ACCA; Tue, 18 May 2021 17:30:30 +0000 (UTC) Received: from [10.10.117.64] (ovpn-117-64.rdu2.redhat.com [10.10.117.64]) by smtp.corp.redhat.com (Postfix) with ESMTP id D8BA018EC9; Tue, 18 May 2021 17:30:29 +0000 (UTC) Subject: Re: [PATCH] fdc: check null block pointer before blk_pwrite To: P J P References: <20200827113806.1850687-1-ppandit@redhat.com> From: John Snow Message-ID: Date: Tue, 18 May 2021 13:30:29 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: <20200827113806.1850687-1-ppandit@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=jsnow@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=216.205.24.124; envelope-from=jsnow@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -31 X-Spam_score: -3.2 X-Spam_bar: --- X-Spam_report: (-3.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.374, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Ruhr-University , QEMU Developers , qemu-block@nongnu.org, Prasad J Pandit Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 8/27/20 7:38 AM, P J P wrote: > From: Prasad J Pandit > > While transferring data via fdctrl_write_data(), check that > current drive does not have a null block pointer. Avoid > null pointer dereference. > Hi PJP. I assume this patch actually covers the exact same thing that the other if cur_drv->blk patch we have been discussing recently does. You may want to combine the Reported-By lines for both. I am dropping this patch from my queue in favor of pursuing our other, more recent and active thread, which I am also now tracking via this gitlab issue: https://gitlab.com/qemu-project/qemu/-/issues/338 > -> https://ruhr-uni-bochum.sciebo.de/s/NNWP2GfwzYKeKwE?path=%2Ffdc_nullptr1 > ==1658854==Hint: address points to the zero page. > #0 blk_inc_in_flight block/block-backend.c:1327 > #1 blk_prw block/block-backend.c:1299 > #2 blk_pwrite block/block-backend.c:1464 > #3 fdctrl_write_data hw/block/fdc.c:2418 > #4 fdctrl_write hw/block/fdc.c:962 > #5 portio_write ioport.c:205 > #6 memory_region_write_accessor memory.c:483 > #7 access_with_adjusted_size memory.c:544 > #8 memory_region_dispatch_write memory.c:1476 > > Reported-by: Ruhr-University > Signed-off-by: Prasad J Pandit > --- > hw/block/fdc.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/hw/block/fdc.c b/hw/block/fdc.c > index e9ed3eef45..dedadac68a 100644 > --- a/hw/block/fdc.c > +++ b/hw/block/fdc.c > @@ -2419,7 +2419,8 @@ static void fdctrl_write_data(FDCtrl *fdctrl, uint32_t value) > if (pos == FD_SECTOR_LEN - 1 || > fdctrl->data_pos == fdctrl->data_len) { > cur_drv = get_cur_drv(fdctrl); > - if (blk_pwrite(cur_drv->blk, fd_offset(cur_drv), fdctrl->fifo, > + if (cur_drv->blk > + && blk_pwrite(cur_drv->blk, fd_offset(cur_drv), fdctrl->fifo, > BDRV_SECTOR_SIZE, 0) < 0) { > FLOPPY_DPRINTF("error writing sector %d\n", > fd_sector(cur_drv)); >